Abstract: | We consider a linear periodic control system with constant matrix multiplying the control in the critical case under the assumption that the mean of the coefficient matrix is block triangular and some blocks of its nonstationary part have incomplete column rank. A linear state feedback control periodic with the same period as the system itself is considered. We obtain necessary and sufficient conditions for the solvability of the asynchronous pole assignment problem, that is, the problem of finding a feedback factor such that the closed-loop system has a strongly irregular periodic solution with desired frequencies. |